Manifold imaging utilizing silica gel activating layer

ABSTRACT

A manifold imaging method and member is disclosed wherein the imaging layer is activated by a liquid activator which is incorporated in the member by means of a gel layer. By exerting pressure on the imaging member the gel activates the imaging layer for use in the manifold imaging process.

United States Patent [191 Kropac Sept. 23, 1975 MANIFOLD IMAGING UTILIZING SILICA GEL ACTIVATING LAYER [75] Inventor: Joseph M. Kropac, Williamson,

[73] Assignee: Xerox Corporation, Stamford,

Conn.

[22] Filed: Dec. 28, 1973 21 Appl. No.: 429,251

[52] U.S. Cl. 96/1 M; 96/l.5; 96/76 R [51] Int. Cl. G03G 5/00; G03B 5/00; G03G 5/04;

G03G 1/48 [58] Field of Search 96/l.5, 28, 76 R;

117/335, 1 M,36.7, 161 ZA, 36.9

[56] References Cited UNITED STATES PATENTS Lindquist et a1 117/367 X 3,303,043 2/1967 Halpaap ct al 117/335 3,393,155 7/1968 Schutte ct al..... 3,598,581 4/1967 Reinis 96/1.5

Primary Examiner-N0rman G. Torchin Assistant Examiner-L. Falasco [5 7] ABSTRACT A manifold imaging method and member is disclosed wherein the imaging layer is activated by a liquid activator which is incorporated in the member by means of a gel layer. By exerting pressure on the imaging member the gel activates the imaging layer for use in the manifold imaging process.

20 Claims, 2 Drawing Figures US Patent Sept. 23,1975

i iw g wt m/ M\ WV ww mwvn u F wh n M M n m WH w n WW MANIFOLD IMAGING UTILIZING SILICA GEL ACTIVATING LAYER I BACKGROUND OF THE INVENTION This invention relates to the manifold imaging process and more particularly to a novel imaging member and method.

There has recently been discovered an imaging technique generally referred to as the manifold imaging method wherein an imaging member comprising a donor layer, imaging layer and receiver layer is employed. The imaging layer is electrically photosensitive and in one form comprises an electrically photosensitive material such as metal-free phthalocyanine dispersed in an insulating binder. Typically, the imaging layer is coated on the donor layer and the coated substrate combined is termed a donor. When needed, in preparation for the imaging operation, the imaging layer is activated as by contacting it with a swelling agent, softening agent, solvent or partial solvent for the imaging layer. The imaging layer is typically exposed to an imagewise pattern of light to which it is sensitive and while sandwiched between the donor and receiver layers and subjected to an electric field the imaging layer fractures upon the separation of the donor and receiver layers providing complementary positive and negative images on the donor and receiver layers in accordance with the image to which it was exposed.

Such manifold imaging method is more fully disclosed in US. Pat. No. 3,707,368 to Van Dorn which patent is hereby incorporated by reference. As is taught in said patent the imaging layer is typically activated by applying thereto an activator material. Subsequent efforts in the manifold imaging science has produced other methods of activation such as thermo-activation as disclosed in US. Pat. No. 3,598,581 to Reinis. Although thermo-activation as disclosed by Reinis eliminates the need for handling liquid activators at the imaging site, such process provides a wax component on the final image. A suitable and convenient means for activating the manifold imaging layer by means of a liquid activator has heretofore not been available.

SUMMARY OF THE INVENTION It is, therefore, an object of this invention to provide an improved manifold imaging method.

Another object of this invention is to provide a novel imaging member useful in the manifold imaging process.

Another object of this invention is to provide a method for conveniently and accurately applying an activator to an imaging layer in the manifold imaging method.

In accordance with this invention there is provided a manifold imaging member and method whereby liquid activator for the imaging layer is incorporated into the imaging member by means of a gel layer which activates the imaging layer at the appropriate time by applying light pressure to the imaging member. Thus the imaging member of this invention incorporates, in addition to the donor, receiver and imaging layer, a fourth layer which carries the activator in the form of a gel. The activator activates the imaging layer so as to render the imaging layer structurally fracturable in response to the combined effects of an applied electric field and exposure to electromagnetic radiation to which the imaging layer is sensitive.

The gel is prepared in accordance with this invention by simply combining the finely divided hydrophobic silica with the liquid activator. The proportion depends upon the nature of the activator and the particular silica employed. In most instances a suitable gel is formed by adding to the activator about 10% to about 20% silica by weight. Typically, suitable gels are formed by combining silica and activator in a wide range concentration depending upon the rigidity desired in the gel. Usually amounts of silica up to about 30% provide gels of sufficient rigidity. Preferably the gel is rigid and holds its shape such that when added to the member it stays in place before and after use. Any suitable liquid activator which forms a gel by the addition of hydrophobic silica can be employed. Typical prior art liquid activators include Sohio Odorless Solvent 3440, an aliphatic (kerosene) hydrocarbon fractions available from the Standard Oil, hydrocarbon paraffin solvents having a boiling point range of from about 350 to 385F, halogenated hydrocarbons, hydrocarbon amides and hydrocarbon amines and other hydrocarbons such as decane and dodecane. As in the prior art the liquid activators are desirably purified so as to eliminate any conductive materials or impurities which such commercial products may contain.

Any suitable hydrophobic finely divided silica can be employed, such silica is commercially available under various tradenames and generally have a particle size in the range of from about 10 to about 30 millimicrons. Examples of such silicas are Silanox 101 and Organo- Sil available from the Cabot Chemical Company, Boston, Massachusetts and Aerosil R-972 available from Degussa Inc., New York, New York. Other similar gel forming silica products can be employed in accordance with this invention. Hydrophobic silica is a specially prepared product from silicon dioxide, a more complete description is found in US. Pat. No. 3,720,617 to Charterji et al., which patent is hereby incorporated by reference.

The gel layer is incorporated into the imaging member in any suitable location. The gel layer may be included either under or over the imaging layer. Preferably the gel layer is coated onto the receiver layer before the member is formed. In this way the member can be shipped or stored in the unactivated state yet when in use liquid activator is provided easily and quickly as indicated above. Thus, there is no need for fluid handling equipment at an imaging apparatus in accordance with this invention. Means for applying pressure can be easily provided as such pressure is usually that which can be easily exerted by hand or by means of a pair of rollers or plates. In the preferred embodiment a pair of rollers if employed to receive the donor and receiver layers in web form which carry the imaging and gel layers.

In another embodiment the gel is applied at the imaging site. Typically such application is by means of a soft bristle brush, extruder or any other commonly known coating mechanism for applying a gel to a surface. As taught in the prior art, the activator can be employed either before or after the image exposure step of the imaging process.

In general, the manifold imaging member of the prior art employing liquid activated imaging layers are also useful in the member and process of this invention. Thus, typical thermoplastic, metal and paper donor and receiver layers of the prior art are also useful herein. In

addition, the typical liquid activated electrically photosensitive imaging layers of the prior art are employed herein. Numerous exemplary materials useful in preparing the donor, receiver and imaging layers are listed in the above-mentioned U.S. Pat. No. 3,707,368.

Here, as in the prior art, the liquid activator to be employed is chosen so as to effect the desired activation of the imaging layer keeping in mind the electrically photosensitive materials and binders employed therein. One of the major advantages provided by the instant invention is the degree of control and accuracy with which the liquid activator can now be applied to the imaging layer. Typically it is desirable to employ sufficient activator to provide the proper physical properties of the imaging layer at the time of imaging yet it is not desirable to add excess activator as it must be removed after image formation. As is indicated by the prior art manifold processes referred to above, excess activator is typically removed from the imaging member by squeegee action of a roller prior to exposure of the imaging layer to electromagnetic radiation. In accordance with the present invention such excess need not occur because the gel layer can be incorporated into the manifold imaging member accurately by such common means as extruder devices normally employed for extruding gels. By controlling the amount of activator in the gel and the amount of the gel incorporated in the imaging member of this invention, a high degree of control'is exercised over the amount of activator finally applied to the imaging layer during the imaging process.

BRIEF DESCRIPTION OF THE DRAWINGS In order that the invention will be more clearly understood, reference is now made to the accompanying drawings in which an embodiment of the invention is illustrated by way of example.

FIG. 1 is a side sectional view of a photosensitive imaging member of this invention.

FIG. 2 is a side sectional view diagrammatically illustrating the process steps of this invention.

Referring now to FIG. 1, imaging layer 2 comprising photosensitive particles 4 dispersed in binder 3, is deposited on an insulating donor substrate sheet 5. The image receiving portion of the manifold set comprises receiver layer 6. In this embodiment gel layer 7 is incorporated between imaging layer 2 and receiver layer 6. In the usual case either or both of layers 5 and 6 are transparent to electromagnetic radiation to which the imaging layer is sensitive and conveniently has electrically conductive outer surfaces.

Referring now to FIG. 2, the first step illustrated in the imaging process is the activation step. In this stage of the imaging process the manifold set comprising electrically insulating donor layer 17, imaging layer 12, electrically insulating receiver layer 16 and gel layer 19 is passed between rollers 26 which apply a slight presnected to potential source 28 through resistor 30. Electrodes 18 and 28 can take any suitable form for impart ing an electrostatic charge to the layers. One convenient form is a pair of conductive rollers.

The manifold set is then advanced to imaging station 27 which it is exposed to light image 29. Light image 29 maybe lightprojected through a transparency or light information projected from an opaque subject. In a continuous operation the light image preferably is projected through a slit so that there is little or no relative motion between the projected image and the manifold set during exposure. Although not shown, other sequences of method steps can occur. For example, a suitably charged imaging layer can be exposed to appropriate radiation before the sandwich is formed. Such a process is fully described in U.S. Pat. No. 3,615,393 hereby incorporated by reference.

Subsequent to imaging receiver layer 16 is separated from donor layer 17 over roller 32 thus fracturing the imaging layer in accordance with the light image to which it was exposed.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The following Examples further specifically illustrate the present invention. The Examples below are intended to illustrate various embodiments of the improved imaging member and method. The parts and percentages are by weight unless otherwise indicated.

EXAMPLE I A gel is first prepared by combining two parts of a hydrophobic silica, Aerosil R-972 to 15 parts of Sohio Odorless Solvent 3440 with constant mixing. The gel which is formed is rigid.

A black color imaging layer is prepared by first providing the x-form metal-free phthalocyanine as described in Example I of the aforementioned U.S. Pat. No. 3,707,368. About 2.5 grams of the x form phthalocyanine is added to about 1.2 grams of Algol Yellow GC, 1,2,5,6-di-(C,C-diphenyl) thiazoleanthraquinone, C. I. No. 67300, available from GAF and about 2.8 grams of purified Irgazine 2 BLT available from Geigy Chemical Co.

A binder is prepared by first dissolving 3 parts of Polyethylene DYLT, 1.5 parts of Paraflint RG, 0.5 parts of Elvax 420 and 2.5 parts of Piccotex 75 in 20 parts of Sohio Odorless Solvent 3440 by heating the mixture with stirring. The solution is allowed to cool and the resulting paste is added to the milled pigment. The pigment/paste mixture is ball milled for about 16 hours. The milled paste is then placed in a polyethane jar which is heated in a water bath at a temperature of 65C for about 2 hours. The paste is then allowed to cool overnight and slurried in about paste of 2- proxanol. The paste-like mixture is then coated on I mil Mylar (a polyester formed by the condensation reaction between ethylene glycol and tetphthalic acid available from E. I. DuPont de Nemours and Co., Inc.) with a No. 22 wire wound drawdown rod to produce a coating thickness when dried of approximately 8 to 10 microns. The coating and one mil Mylar sheet is then dried in the dark at a temperature of about 43C. for 3 minutes. A receiver sheet of Mylar is placed over the donor. The receiver sheet is lifted up and the imaging layer is coated with the gel as prepared above by a wide camels hair brush saturated with the gel. The receiver sheet is then lowered back down and a hand roller is rolled slowly over the closed manifold sandwich with light pressure to force the solvent out of the gel. The manifold sandwich is placed donor side down on the tin oxide surface of a NESA glass plate and a black paper electrode is placed over the receiver. The electrodes are connected to a 9,000 volt DC. power supply in series with a 5,500 megohm resistor with a NESA glass electrode being the positive electrode and the black opaque electrode being the negative electrode. With the voltage applied, a white incandescent light image is projected upward through the NESA glass with an illumination of an f stop of l l for 0.5 seconds to provide about 0.25 foot candle seconds incident energy. After exposure, the receiver sheet together with the opaque electrode is peeled from the set with the potential source still connected. Upon separation the imaging layer fractures in imagewise configuration yielding a pair of images with a suplicate of the original on the donor sheet and a reversal or negative image on the receiver sheet.

EXAMPLE II The procedure of Example I is repeated with the exception that a straight chain hydrocarbon paraffin solvent available under the trade name AEC-n-paraffin solvent, boiling points range 353 to 383F, is employed in place of the Sohio Odorless Solvent. Similar results are obtained.

EXAMPLE Ill The procedure of Example I is repeated with the exception that Silanox 101 is employed in place of the Aerosil R-972. Similar results are obtained.

Other modifications and ramifications of the present invention will occur to those skilled in the art upon a reading of the present disclosure. There are intended to be included within the scope of this invention.

What is claimed is:

1. In a manifold imaging member comprising a donor layer, receiver layer, an electrically photosensitive imaging layer and an activator layer, the improvement wherein said activator layer is in the form of a gel comprising a finely divided hydrophobic silica and a liquid activator for said imaging layer.

2. An image member of claim 1 wherein at least one of said donor and receiver layers is transparent.

3. The imaging layer of claim 1 wherein said donor and said receiver layers are transparant thermoplastic materials.

4. The imaging member of claim 1 wherein the silica gel contains finely divided silica having a particle size in the range of from about millimicrons to about 30 millimicrons.

5. The imaging member of claim 4 wherein said gel layer contains a solvent activator for said imaging layer.

6. The imaging member of claim 4 wherein said gel layer contains a partial solvent activator for said imaging layer.

7. An imaging member of claim 4 wherein said gel layer contains a swelling agent activator for said imaging layer.

8. In a manifold imaging member comprising a donor layer, an electrically photosensitive imaging layer residing on said donor layer, an activator layer residing on said imaging layer and a receiver layer over said activator layer, the improvement wherein said activator layer comprises a mixture of finely divided hydrophobic silica and a liquid activator for said imaging layer.

9. An imaging layer of claim 8 wherein said imaging layer comprises an electrically photosensitive material dispersed in a binder.

10. An imaging member of claim 1 wherein said imaging layer comprises an electrically photosensitive material dispersed in a binder.

11. An imaging member of claim ,1 wherein said imaging layer is of a'black color.

12. An imaging member of claim 8 wherein said imaging layer is of a black color.

13. An imaging member of claim 1 wherein said gel layer is coated on said receiver sheet.

14. An imaging process which comprises the steps of:

1. providing an imaging member of claim 1;

2. applying pressure to said imaging member whereby said activator layer provides a liquid activator for said imaging layer and renders said imaging layer structurally fracturable in response to the combined effects of an applied electric field and exposure to electromagnetic radiation to which said imaging layer is sensitive;

3. subjecting said imaging layer to an electrical field and exposing said imaging layer to electromagnetic radiation to which it is sensitive, and;

4. separating said donor and receiver layers while said member is subjected to said electrical field whereby said imaging layer fractures in imagewise configuration providing a positive image on one said donor and receiver layers and a negative image on the other.

15. The process of claim 14 wherein said gel activator layer resides between said imaging layer and said receiver layer.

16. The method of claim 14 wherein said pressure is applied by means of a pair of pressure rollers.

17. The method of claim 14 wherein at least one of said donor and receiver layers is at least partially transparent to electromagnetic radiation to which said imaging layer is sensitive and said exposure is through said layer.

18. The method of claim 14 wherein said gel layer comprises up to about 30% by weight hydrophobic submicroscopic silica.

19. The imaging method of claim 14 wherein said imaging layer is coated on said donor layer and said gel activator layer is coated on said imaging layer.

20. The imaging process of claim 14 wherein said gel activator layer is coated on said receiver layer. 

1. IN A MANIFOLD IMAGING MEMBER COMPRISING A DONOR LAYER, RECEIVER LAYER, AN ELECTRICALLY PHOTOSENSITIVE IMAGING LAYER AND AN ACTIVATOR LAYER, THE IMPROVEMENT WHEREIN SAID ACTIVATOR LAYER IS IN THE FORM OF A GEL COMPRISING A FINELY DIVIDED HYDROPHOBIC SILICA AND A LIQUID ACTIVATOR FOR SAID IMAGING LAYER.
 2. An image member of claim 1 wherein at least one of said donor and receiver layers is transparent.
 2. applying pressure to said imaging member whereby said activator layer provides a liquid activator for said imaging layer and renders said imaging layer structurally fracturable in response to the combined effects of an applied electric field and exposure to electromagnetic radiation to which said imaging layer is sensitive;
 3. subjecting said imaging layer to an electrical field and exposing said imaging layer to electromagnetic radiation to which it is sensitive, and;
 3. The imaging layer of claim 1 wherein said donor and said receiver layers are transparant thermoplastic materials.
 4. The imaging member of claim 1 wherein the silica gel contains finely divided silica having a particle size in the range of from about 10 millimicrons to about 30 millimicrons.
 4. separating said donor and receiver layers while said member is subjected to said electrical field whereby said imaging layer fractures in imagewise configuration providing a positive image on one said donor and receiver layers and a negative image on the other.
 5. The imaging member of claim 4 wherein said gel layer contains a solvent activator for said imaging layer.
 6. The imaging member of claim 4 wherein said gel layer contains a partial solvent activator for said imaging layer.
 7. An imaging member of claim 4 wherein said gel layer contains a swelling agent activator for said imaging layer.
 8. In a manifold imaging member comprising a donor layer, an electrically photosensitive imaging layer residing on said donor layer, an activator layer residing on said imaging layer and a receiver layer over said activator layer, the improvement wherein said activator layer comprises a mixture of finely divided hydrophobic silica and a liquid activator for said imaging layer.
 9. An imaging layer of claim 8 wherein said imaging layer comprises an electrically photosensitive material dispersed in a binder.
 10. An imaging member of claim 1 wherein said imaging layer comprises an electrically photosensitive material dispersed in a binder.
 11. An imaging member of claim 1 wherein said imaging layer is of a black color.
 12. An imaging member of claim 8 wherein said imaging layer is of a black color.
 13. An imaging member of claim 1 wherein said gel layer is coated on said receiver sheet.
 14. An imaging process which comprises the steps of:
 15. The process of claim 14 wherein said gel activator layer resides between said imaging layer and said receiver layer.
 16. The method of claim 14 wherein said pressure is applied by means of a pair of pressure rollers.
 17. The method of claim 14 wherein at least one of said donor and receiver layers is at least partially transparent to electromagnetic radiation to which said imaging layer is sensitive and said exposure is through said layer.
 18. The method of claim 14 wherein said gel layer comprises up to about 30% by weight hydrophobic submicroscopic silica.
 19. The imaging method of claim 14 wherein said imaging layer is coated on said donor layer and said gel activator layer is coated on said imaging layer.
 20. The imaging process of claim 14 whereiN said gel activator layer is coated on said receiver layer. 